The Vitamin-pill Hustle Eating Sensibly The Best Way To Get The Proper Nutrients

November 25, 1985|By Don Colburn, Washington Post

Early in this century, scientists searching for the cause of such diseases as beriberi, rickets and scurvy made a startling discovery: They did not come from germs in the air or toxins in the food, but from something missing from the diet.

That something is now known as a vitamin.

Vitamins are organic (carbon-containing) molecules that the body cannot do without and does not produce on its own. They are chemical catalysts -- they make things happen.

''A vitamin is like a traffic cop at a busy intersection with cars shooting past,'' said Dr. Victor Herbert, chief of the hematology and nutrition research laboratory at the Bronx (N.Y.) Veterans Administration Medical Center.

In Herbert's analogy, the cars are the carbohydrates, fats and proteins that the body uses for energy. Vitamins speed up the traffic flow -- the chemical reactions involving those sources of energy.

Vitamins don't provide energy, any more than a traffic cop provides traffic, said Herbert, a member of the National Academy of Sciences' committee on recommended dietary allowances. But they help determine the rate at which the body consumes fuel.

Prolonged lack of any vitamin in the diet causes serious illness. The best-known vitamin-deficiency diseases are beriberi (from lack of vitamin B1), night blindness (from lack of A), pellagra (from lack of B3), rickets (from lack of D), pernicious anemia (from lack of B12) and scurvy (from lack of C). Vitamins are big business. Americans spend nearly $3 billion a year on vitamin and mineral pills to supplement their intake from ordinary food. More than one in three Americans, surveys show, take vitamin supplements regularly. Of the $3 billion, Herbert estimated that ''probably about 1 percent'' is medically necessary. The rest, he said, is a waste.

''People have an almost irrational love affair with vitamins,'' said William Jarvis, chairman of the department of public-health science at Loma Linda University in California and president of the National Council against Health Fraud. ''These things are like sacred cows.''

The word itself has come to stand for vim, vigor and vitality and as marketers have learned, a kind of can-do magic. It was coined in 1911 by the Polish biochemist Casimir Funk, who discovered that rice husks seemed to prevent beriberi in pigeons. He thought he had found the nutritional missing link.

Actually, what Funk had found was a substance later identified as thiamine, or vitamin B1. He called it ''vitamine'' -- a combination of the Latin word ''vita'' (meaning ''life'') and ''amine'' (because he erroneously thought that it was in a class of chemical compounds called amines).

In the 1920s the ''e'' in ''vitamine'' was dropped, because scientists found that not all vitamins were amines after all.

Vitamins were identified by letter because their exact chemical composition was not known. The original B vitamin turned out to be several different vitamins, and numbers had to be added.

Later it was discovered that some substances identified as vitamins were not essential to human health, and they were removed from the vitamin list, leaving gaps in the numbers.

In all, 13 vitamins have been identified as essential to the hu man diet. The last, B12, was discovered in 1948, and most experts say it is unlikely that more vitamins will be found.

Because patients have survived for more than 10 years on intravenous feedings fortified only with the 13 known vitamins, the existence of a 14th essential vitamin seems doubtful.

Vital as they are, vitamins are needed by the body in only the tiniest amounts. A few vitamins, such as vitamin A, occur in more than one form and are counted in international units (IUs), a measure of biological activity. Most are measured in milligrams (thou- sandths of a gram) or micrograms (millionths of a gram).

The recommended dietary allowance (RDA) of vitamin B12 for adults is 6 micrograms a day; a single ounce of B12 would satisfy the daily need of 4,724,916 people. And one person's RDA for all 13 vitamins would fill about one-eighth of a teaspoon.

Vitamins come in two main categories: fat-soluble and water-soluble.

Fat-soluble vitamins (A, D, E and K) are absorbed through the intestinal walls and can be stored in the body fat for long periods of time. Because they accumulate in the body, fat-soluble vitamins can become toxic if consumed in excessive amounts. As little as five times the RDA for vitamin A, taken regularly, can cause brain and liver damage. (A plant form called beta- carotene, which the body converts to vitamin A, is much less toxic.)

Water-soluble vitamins (B-complex and C) cannot be stored in the body for long, because they dissolve in water and are released in the urine.

The rapid excretion of surplus water-soluble vitamins can easily be demonstrated, as Herbert and Dr. Stephen Barrett point out in their book, Vitamins and ''Health'' Foods: The Great American Hustle.